<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width,initial-scale=1,user-scalable=0">
    <title>上传宝宝头像</title>
    <link rel="stylesheet" href="/static/weui-1.0.2/dist/style/weui.css"/>
    <link rel="stylesheet" href="/static/weui-1.0.2/dist/example/example.css"/>
    <link rel="stylesheet" href="https://res.wx.qq.com/open/libs/weui/0.3.0/weui.css" />
    <script src="/static/admin/css/jquery-3.0.0.min.js"></script>
</head>
<style>
    .you{
        margin-left:17px;
    }
</style>
<body>
<div class="weui_uploader">
    <div class="weui_uploader_hd weui_cell">
        <div class="weui_cell_bd weui_cell_primary">图片上传</div>
        <div class="weui_cell_ft js_counter">0/6</div>
    </div>
    <div class="weui_uploader_bd">
        <ul class="weui_uploader_files">
            <!-- 预览图插入到这 --> </ul>
        <div class="weui_uploader_input_wrp">
            <input class="weui_uploader_input js_file" type="file" accept="image/jpg,image/jpeg,image/png,image/gif" multiple=""></div>
    </div>
</div>

<script>
    $(function () {
        // 允许上传的图片类型
        var allowTypes = ['image/jpg', 'image/jpeg', 'image/png', 'image/gif'];
        // 1024KB，也就是 1MB
        var maxSize = 1024 * 1024;
        // 图片最大宽度
        var maxWidth = 300;
        // 最大上传图片数量
        var maxCount = 1;
        $('.js_file').on('change', function (event) {
            var files = event.target.files;

            // 如果没有选中文件，直接返回
            if (files.length === 0) {
                return;
            }

            for (var i = 0, len = files.length; i < len; i++) {
                var file = files[i];
                var reader = new FileReader();

                // 如果类型不在允许的类型范围内
                if (allowTypes.indexOf(file.type) === -1) {
                    $.weui.alert({text: '该类型不允许上传'});
                    continue;
                }

                if (file.size > maxSize) {
                    $.weui.alert({text: '图片太大，不允许上传'});
                    continue;
                }

                if ($('.weui_uploader_file').length >= maxCount) {
                    $.weui.alert({text: '最多只能上传' + maxCount + '张图片'});
                    return;
                }

                reader.onload = function (e) {
                    var img = new Image();
                    img.onload = function () {
                        // 不要超出最大宽度
                        var w = Math.min(maxWidth, img.width);
                        // 高度按比例计算
                        var h = img.height * (w / img.width);
                        var canvas = document.createElement('canvas');
                        var ctx = canvas.getContext('2d');
                        // 设置 canvas 的宽度和高度
                        canvas.width = w;
                        canvas.height = h;
                        ctx.drawImage(img, 0, 0, w, h);
                        var base64 = canvas.toDataURL('image/png');

                        // 插入到预览区
                        var $preview = $('<li class="weui_uploader_file weui_uploader_status" style="background-image:url(' + base64 + ')"><div class="weui_uploader_status_content">0%</div></li>');
                        $('.weui_uploader_files').append($preview);
                        var num = $('.weui_uploader_file').length;
                        $('.js_counter').text(num + '/' + maxCount);

                        // 然后假装在上传，可以post base64格式，也可以构造blob对象上传，也可以用微信JSSDK上传

                        var progress = 0;
                        function uploading() {
                            $preview.find('.weui_uploader_status_content').text(++progress + '%');
                            if (progress < 100) {
                                setTimeout(uploading, 30);
                            }
                            else {
                                // 如果是失败，塞一个失败图标
                                //$preview.find('.weui_uploader_status_content').html('<i class="weui_icon_warn"></i>');
                                $preview.removeClass('weui_uploader_status').find('.weui_uploader_status_content').remove();
                            }
                        }
                        setTimeout(uploading, 30);
                    };

                    img.src = e.target.result;
                    var  url = "{:url('upload2')}";
                    $.post(url, { img: e.target.result},function(res){
                        if(res.img!=''){
                            alert('upload success');
                            $('#showimg').html('<img src="' + res.img + '">');
                        }else{
                            alert('upload fail');
                        }
                    },'json');
                };
                reader.readAsDataURL(file);

            }
        });
    });

</script>
</body>
</html>